The present invention relates to a method and a device for three-dimensional display. More particularly, this invention relates to a method and a device for three-dimensional display using a variable focusing lens combined with a two-dimensional display.
The most popular method for three-dimensional display by prior art is one using the binocular parallax phenomenon. This method utilizes the principle that the human brain perceives a three-dimensional image when each eye sees one of two images that are measured at different angles. This method does not actually generate a three-dimensional image in the space. Rather, parallax by the observer's eyes is utilized. Therefore, this method has disadvantages that various factors including arbitrary distribution of the viewer's position, binocular disparity due to deviations in the distance between the two eyes, vergence, fatigue accumulation in the eye, accommodation, watching by more than one viewers, the relative position change of the three-dimensional image due to viewer's movement, etc., are involved, and such factors must be considered in order to provide proper three-dimensional display.
Holography is a three-dimensional display method that generates a real image in the space. Holography has been used for three-dimensional image display very limitedly due to its technical complexity and high manufacturing cost.
U.S. Pat. No. 4,834,512 to Austin discloses a 3D display having a 2D display, a fluid-filled variable focusing lens, and control means for controlling the display and the lens. The 2D display sequentially presents 2D images representative of the cross sections of an object at different depths. The fluid-filled variable focusing lens is disposed in front of the 2D display and has a membrane that responds to the pressure of the fluid within the lens. Austin's display has a disadvantage that since the focus changing speed of the fluid-filled lens is slow, the display is unsuitable for displaying realistic 3D images.
U.S. Pat. No. 5,986,811 to Wohlstadter discloses an imaging method and system for creating 3D image from a 2D image having a plurality of image points. The imaging system includes an array of micro-lenses having variable focusing length, and means for holding the micro-lenses in alignment with the image points of the 2D display.
New three-dimensional image display method and device, which can meet requirements related to eye fatigue, watching by more than one viewers, practicality of the relative distance between a three-dimensional image and the viewer, 2D/3D compatibility or exchangeability, color expression and resolution that equal or exceed those of HDTV, low manufacturing cost, and no significant data amount increase, have long been in need.